Turbocharger system having an air-cooled wastegate actuator

ABSTRACT

A turbocharger system is provided herein. The turbocharger system includes a turbine positioned downstream of a combustion chamber, a turbine bypass conduit in fluidic communication with a turbine inlet and a turbine outlet, a wastegate positioned in the turbine bypass conduit, and an air-cooled wastegate actuator adjusting the position of the wastegate, the air-cooled wastegate actuator receiving cooling airflow from an intake conduit positioned upstream of a compressor mechanically coupled to the turbine.

FIELD

The present disclosure relates to a wastegate actuator in a turbochargersystem in a vehicle.

BACKGROUND/SUMMARY

Boosting device, such as turbochargers and superchargers, may be used inengines. Turbochargers may increase the power output of the engine for agiven displacement as compared to a naturally aspirated engine.

It may be desirable to decrease the flow path between the turbine in theturbocharger and the combustion chambers by positioning the turbineclose to the exhaust ports of the cylinders. Such positioning decreaseslosses in the exhaust gas flow, thereby enabling the speed of theturbine to increase. The increased turbine speed increases the amount ofcompression provided by the compressor. As a result, the power output ofthe engine may be increased.

However, due to the proximity of the turbine to the combustion chamber,the turbine and surrounding components may experience elevatedtemperatures. In some engines the exhaust manifold and turbine housingmay have radiating surface temperatures over 900 degrees Celsius.Consequently, the turbine and surrounding components may experiencethermal degradation, decreasing component longevity. For example,wastegates may become inoperable during such over-temperatureconditions. Wastegate actuators may be particularly susceptible toelevated temperatures due to the characteristics of the valve controlcomponent included therein, such as circuits, solenoids, etc.

U.S. Pat. No. 4,630,445 discloses a turbocharger with a wastegate valvefor adjusting the amount of exhaust gas provided to a turbine in theturbocharger. A heat shield is used in the wastegate to protect thevalve stem in the wastegate from elevated temperature conditions. TheInventors have recognized several drawbacks with the wastegate valvedisclosed in U.S. Pat. No. 4,630,445. For example, the heat shield mayreduce the amount of heat transferred to the wastegate but does notactively cool the wastegate. Furthermore, heat may be transferred to thewastegate components from paths which are not impeded by the heatshield. Consequently, the wastegate valve disclosed in U.S. Pat. No.4,630,445 may still experience over-temperature conditions during engineoperation.

Likewise, attempts have been made to cool the wastegate actuator viaengine coolant diverted from the engine cooling system. However,utilizing engine coolant to cool the wastegate actuator may require highintegrity plumbing and increases the likelihood of coolant leaks throughnew leak paths. The high integrity plumbing may also be costly.

As such in one approach a turbocharger system is provided. Theturbocharger system includes a turbine positioned downstream of acombustion chamber, a turbine bypass conduit in fluidic communicationwith a turbine inlet and a turbine outlet, a wastegate positioned in theturbine bypass conduit, and an air-cooled wastegate actuator adjustingthe position of the wastegate, the air-cooled wastegate actuatorreceiving cooling airflow from an intake conduit positioned upstream ofa compressor mechanically coupled to the turbine.

In this way, cooling is provided to the wastegate actuator via intakeair, thereby reducing the thermal stress on the actuator. Consequently,the longevity of the wastegate actuator may be increased when aircooling is provided. Furthermore, when intake air is used to cool thewastegate actuator, cooling of the wastegate actuator via engine coolantmay be avoided or reduced, if desired. As a result, the cost andcomplexity of the engine is reduced and the likelihood of coolant leaksand potential cooling system degradation is reduced.

The above advantages and other advantages, and features of the presentdescription will be readily apparent from the following DetailedDescription when taken alone or in connection with the accompanyingdrawings. It should be understood that the summary above is provided tointroduce in simplified form a selection of concepts that are furtherdescribed in the detailed description. It is not meant to identify keyor essential features of the claimed subject matter, the scope of whichis defined uniquely by the claims that follow the detailed description.Furthermore, the claimed subject matter is not limited toimplementations that solve any disadvantages noted above or in any partof this disclosure. Additionally, the above issues have been recognizedby the inventors herein, and are not admitted to be known.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a vehicle having an engine including a turbocharger system;

FIG. 2 shows a vehicle having an engine including a turbocharger system;

FIG. 3 shows a detailed view of the branch intake conduit inlet includedin the turbocharger system shown in FIG. 1;

FIG. 4 shows a detailed view of the wastegate actuator included in theturbocharger system shown in FIG. 2;

FIG. 5 shows a detailed view of the wastegate actuator included in theturbocharger system shown in FIG. 1; and

FIG. 6 shows a method for operation of a turbocharger system, such asthe turbocharger system of FIG. 1 or 2.

DETAILED DESCRIPTION

A turbocharger system having an air-cooled wastegate actuator isdescribed herein. The wastegate actuator converts electrical controlsignals received from a control system into mechanical actuation. Themechanical actuation is translated from the wastegate actuator to thewastegate valve in the turbine bypass conduit. Intake air may be routedto the wastegate actuator to cool the actuator, and then be routed backto the intake system. In one example, un-compressed intake air may berouted to the wastegate actuator to cool the actuator and then returnedback to the compressor inlet. In this way, exhaust heat transferred tothe wastegate actuator may be dissipated in the cooling air. Further,when using a charge-air cooling downstream of the compressor, the warmedintake air can then be cooled before being ingested in the engine.

Thus, in one embodiment, the air-cooled wastegate actuator receivesintake air from the intake system to reduce the temperature of thewastegate actuator, thereby reducing the likelihood of wastegatedegradation from elevated temperatures. In one example, the wastegateactuator may be positioned adjacent the wastegate and turbine, near theengine exhaust. In other examples, the air-cooled wastegate actuator maybe positioned in the engine's intake system. In this way, the intakesystem may serve a dual use, providing intake air to the engine, as wellas cooling the wastegate actuator. Therefore, routing engine coolant tothe wastegate actuator, may be avoided or reduced, if desired.Consequently, the complexity and cost of the engine may be reduced whileincreasing the longevity of the wastegate actuator.

FIGS. 1 and 2 show first and second examples of a turbocharger systemincluded in an engine of a vehicle. FIG. 3-5 show detailedconfigurations of the turbocharger systems shown in FIGS. 1 and 2. FIG.6 shows a method for operation of a turbocharger system.

FIG. 1 shows a schematic depiction of a vehicle 50 including an internalcombustion engine 52 having a turbocharger system 54. The turbochargersystem 54 may include a turbocharger 56 having a compressor 58mechanically coupled to a turbine 60. A shaft 62 is shown coupling thecompressor 58 to the turbine 60. In this way, the compressor 58 isrotationally coupled to the turbine 60. However, it will be appreciatedthat the compressor may be coupled to the turbine via alternate oradditional linkage (e.g., mechanical linkage). The compressor 58 ispositioned upstream of a combustion chamber 88 and the turbine 60 ispositioned downstream of the combustion chamber.

The compressor 58 is configured to receive intake air from an intakeconduit 64. Therefore, the intake conduit 64 is positioned upstream ofthe compressor 58. The intake conduit 64 is an un-boosted intakeconduit, in the depicted example. Thus, the intake conduit 64 includesan outlet 66 in fluidic communication (e.g., direct fluidiccommunication) with a compressor inlet 68 included in the compressor 58.The compressor inlet 68 is generically depicted via a box. The intakeconduit 64 is configured to receive ambient air. Arrow 70 denotes thegeneral flow of intake air through the intake conduit 64. An air filter72 is coupled to (e.g., positioned within) the intake conduit 64. Theair filter 72 is configured to remove unwanted particulates from the airflowing through the intake conduit.

Another intake conduit 74 is coupled to the intake conduit 64. Theintake conduit 74 is a branch intake conduit in the depicted example.Thus, the intake conduit 74 is in parallel fluidic communication withthe intake conduit 64. The general flow of intake air through the intakeconduit 74 is denoted via arrow 76. The intake conduit 74 includes aninlet 78 and an outlet 80. The inlet 78 and outlet 80 open into upstreamand downstream locations respectively in the intake conduit 64. However,in other examples, the inlet 78 may not be coupled to the intake conduit64, but instead may receive ambient air from the surroundingenvironment. However, when the inlet 78 is coupled to the intake conduit74 the conduit receives filtered intake air, reducing the likelihood offouling of an air-cooler wastegate actuator 116, which may be coupled tothe intake conduit 74, discussed in greater detail herein. Additionally,coupling the inlet 78 to the intake conduit 74 as opposed to receivingambient air at the inlet 78 impedes unfiltered air from being introducedinto the combustion chamber 88, which may degrade combustion operation.Therefore, if the inlet 78 is configured to receive ambient air an airfilter may be coupled to (e.g., positioned within) the inlet 78 in oneexample. The intake conduit 74 may have a smaller cross-sectional areathan the intake conduit 64 in some examples. However, other relativesizes have been contemplated. A fan 79 may be coupled to the branchintake conduit 74, in some examples. The fan 79 may be used to increasethe airflow through the intake conduit 74. However in other examples,just the pressure differential between the inlet and the outlet of theintake conduit 74 may be used to flow air therethrough. A valve 75 maybe coupled to the intake conduit 74. The valve 75 may be configured toadjust the amount of airflow travelling through the intake conduit 74.The valve 75 may receive control signals from a controller 150 indicatedvia signal line 77. As shown, the valve is positioned upstream of awastegate actuator 116. However, other valve positions have beencontemplated such as downstream of the wastegate actuator 116. In otherexamples, the valve 75 may not be coupled to the intake conduit 74.

The compressor 58 includes a compressor outlet 81 in fluidiccommunication with an inlet 82 of an intake conduit 84. Arrow 90 denotesthe general airflow direction through the conduit 84. The compressor 58is configured to increase the pressure of the intake air travellingtherethrough. In this way, boost may be provided to engine 52.Therefore, the intake conduit 84 is a boosted intake conduit in thedepicted example. However, other intake system configurations have beencontemplated. The intake conduit 84 also includes an outlet 86 influidic communication with a combustion chamber 88 in the engine 52. Insome examples, the intake conduit 84 may be in fluidic communicationwith an intake manifold (not shown). The intake manifold may beconfigured to supply intake air to the combustion chamber 88. An intakevalve 170 and an exhaust valve 172 are coupled to the combustion chamber88. It will be appreciated that the engine 52 may include at least oneintake valve and exhaust valve per combustion chamber. The intake andexhaust valves configured to cyclically open to facilitate combustionoperation in the combustion chamber. A piston 91 is positioned in thecombustion chamber 88.

During operation, the combustion chamber 88 in the engine 52 typicallyundergoes a four stroke cycle: the cycle includes the intake stroke,compression stroke, expansion stroke, and exhaust stroke. In amulti-cylinder engine the four stroke cycle may be carried out inadditional combustion chambers. During the intake stroke, generally,exhaust valve 172 closes and intake valve 170 opens. Air is introducedinto combustion chamber 88 via an intake manifold, for example, andpiston 91 moves to the bottom of the combustion chamber so as toincrease the volume within combustion chamber 88. The position at whichpiston 91 is near the bottom of the combustion chamber and at the end ofits stroke (e.g. when combustion chamber 88 is at its largest volume) istypically referred to by those of skill in the art as bottom dead center(BDC). During the compression stroke, intake valve 170 and exhaust valve172 are closed. Piston 91 moves toward the cylinder head so as tocompress the air within combustion chamber 88. The point at which piston91 is at the end of its stroke and closest to the cylinder head (e.g.when combustion chamber 88 is at its smallest volume) is typicallyreferred to by those of skill in the art as top dead center (TDC). In aprocess hereinafter referred to as injection, fuel is introduced intothe combustion chamber. In a process hereinafter referred to asignition, the injected fuel is ignited by known ignition devices such asa spark plug 174, resulting in combustion. Additionally or alternativelycompression may be used to ignite the air/fuel mixture. During theexpansion stroke, the expanding gases push piston 91 back to BDC. Acrankshaft may convert piston movement into a rotational torque of therotary shaft. Finally, during the exhaust stroke, exhaust valve 172opens to release the combusted air-fuel mixture to an exhaust manifoldand the piston returns to TDC. Note that the above is described merelyas an example, and that intake and exhaust valve opening and/or closingtimings may vary, such as to provide positive or negative valve overlap,late intake valve closing, or various other examples. Additionally oralternatively compression ignition may be implemented in the combustionchamber 88.

A charge air cooler 92 and a throttle 94 are coupled to the intakeconduit 84 in the depicted example. However, in other examples, thecharge air cooler and/or throttle may not be coupled to the intakeconduit 84. Further in the depicted example, the throttle 94 ispositioned downstream of the charge air cooler 92. However, in otherexamples the throttle may be positioned upstream of the charge aircooler.

An exhaust conduit 96 may also be in fluidic communication with thecombustion chamber 88. Thus, the exhaust conduit 96 may receive exhaustgas from the combustion chamber 88 during engine operation and includesan inlet 97. Arrow 98 depicts the general exhaust gas flow through theexhaust conduit 96.

The exhaust conduit 96 includes an outlet 100 in fluidic communicationwith a turbine inlet 102 of the turbine 60. The turbine 60 may includeturbine blades configured to receive exhaust gas from the turbine inlet102, in some examples.

An exhaust conduit 104 is in fluidic communication with a turbine outlet106. Specifically, the exhaust conduit 104 includes an inlet 105 influidic communication with turbine outlet 106. The exhaust conduit 104is configured to flow exhaust gas to the surrounding environment. Arrow107 denotes the general flow of exhaust gas through the exhaust conduit104.

A turbine bypass conduit 108 is included in the turbocharger system 54.The turbine bypass conduit 108 includes a bypass conduit inlet 110positioned upstream of the turbine 60 and opening into the exhaustconduit 96 and a bypass conduit outlet 112 positioned downstream of theturbine 60 and opening into the exhaust conduit 104. Therefore, theturbine bypass conduit 108 is in fluidic communication with the turbineinlet 102 and the turbine outlet 106. Specifically, in some examples,the turbine bypass conduit may be directly coupled to the turbine inlet102 and the turbine outlet 106. However, other turbine bypass conduitconfigurations have been contemplated. Arrow 109 depicts the generaldirection of exhaust gas flow through the turbine bypass conduit 108when a wastegate 114 is open. It will be appreciated that the relativesizes (e.g., cross-sectional areas) of the turbine bypass conduit 108and the exhaust conduits 96 and 104 may be selected based on the desiredperformance characteristics of the turbocharger.

The wastegate 114 is coupled to the turbine bypass conduit 108.Specifically in some examples, the wastegate 114 may be positioned inthe turbine bypass conduit 108. The wastegate 114 is configured toadjust the exhaust gas flow through the turbine bypass conduit 108. Inthis way, the speed of the turbine may be regulated. In some examples,the wastegate may have an open configuration in which exhaust gas canflow through the turbine bypass conduit 108 and a closed configurationin which exhaust gas is substantially inhibited from flowing through theturbine bypass conduit. It will be appreciated that in some examples thewastegate 114 may a number of open configurations, each configurationallowing a different amount of exhaust gas to flow through the turbinebypass conduit. Further, in some examples, the wastegate 114 may bediscretely or continuously adjustable in configurations which havevarying degrees of opening. In this way, the wastegate 114 may preciselyadjust the speed of the turbine 60. In some examples, the wastegate 114may include a valve 115 that adjusts an opening in the bypass conduit.

An air-cooled wastegate actuator 116 is coupled to the wastegate 114 inthe depicted example. The air-cooled wastegate actuator 116 and thewastegate 114 may be included in the turbocharger system 54. In oneexample, wastegate actuator 116 includes an electrically controlledsolenoid, or an electronically controlled pneumatic actuator. Line 118denotes the coupling of the air-cooled wastegate actuator 116 to thewastegate 114, including the valve forming the wastegate. The couplingforming line 118 may include a mechanical linkage in one example,coupling the waste-gate actuator's controlled movement with movement ofa valve of the wastegate. In this way, the air-cooled wastegate actuator116 is configured to adjust the wastegate 114. Specifically, theair-cooled wastegate actuator 116 may be configured to adjust the amountof exhaust gas passing through the turbine bypass conduit 108. In thisway, the speed of the turbine 60 may be adjusted.

As explained herein, the air-cooled wastegate actuator 116 may receivecooling airflow from the branch intake conduit 74 and therefore alsoreceive cooling airflow from the intake conduit 64 in the depictedexample. However, in the example depicted in FIG. 2, the air-cooledwastegate actuator 116 directly receives cooling airflow from the intakeconduit 64. In this way, the air-cooled wastegate actuator 116 may becooled via intake airflow, thereby reducing the temperature of thewastegate actuator. Further, it may be positioned further from theexhaust, also reducing exhaust heat transferred from the exhaust.

In some examples, the air-cooled wastegate actuator 116 may be apneumatic wastegate actuator. In such an example, the air-cooledwastegate actuator may include a diaphragm coupled to a spring. Apneumatic conduit may provide a boosted air pressure to the diaphragm.Line 120 denotes the pneumatic conduit. The pneumatic conduit 120includes a pneumatic conduit inlet 122 opening into the intake conduitand a pneumatic conduit outlet 124 opening into the diaphragm in thewastegate actuator. The wastegate actuator may adjust the wastegatebased on the pressure exerted on the diaphragm. For example, thewastegate actuator may increase the amount of airflow through thewastegate as the pressure against the diaphragm increases and/or thewastegate may open when the pressure against the diaphragm exceeds apredetermined threshold value. However, other control methods have beencontemplated. It will be appreciated that the pressure on the diaphragmis proportional to the boost air pressure downstream of the compressor58. The spring and diaphragm may be coupled to the wastegate 114 vialinkage (e.g., mechanical linkage). In this way, the pneumatic wastegateactuator 116 receives boosted air from an intake conduit positioneddownstream of the compressor. When the air-cooled wastegate actuator 116is a pneumatic wastegate actuator, line 118 denotes pneumatic linkagebetween the wastegate actuator and the wastegate. However, in otherexamples, the pneumatic conduit may not be included in the turbochargersystem 54. Further in some examples, the wastegate actuator 116 may becoupled to the wastegate mechanically (e.g., via mechanical linkage).

In some examples, the air-cooled wastegate actuator 116 may include asolenoid and/or a motor for adjusting the wastegate. Therefore, theair-cooled wastegate actuator 116 may have electronic driven circuitry.The solenoid and/or motor may be controlled by a controller 150. Moregenerally, the air-cooled wastegate actuator 116 may be controlled bythe controller 150 and therefore receive control signals from acontroller, denoted via line 117. The controller 150 is shown in FIG. 1as a conventional microcomputer including: microprocessor unit 152,input/output ports 154, read-only memory 156, random access memory 158,keep alive memory 160, and a conventional data bus. Controller 12 mayreceive various signals from sensors coupled to engine 10. For example,controller 12 may receive signals from a position sensor 162 coupled toan accelerator pedal 164 for sensing accelerator position adjusted byfoot 166.

The controller 150 may receive signals from sensors in the vehicle 50such as a pressure sensor 180 electronically coupled to the controllervia a signal line 181, a pressure sensor 182 electronically coupled tothe controller via a signal line 183, a temperature sensor 184electronically coupled to the controller via a signal line 185. Asshown, the pressure sensor 180 is coupled to the intake conduit 84, thepressure sensor 182 is coupled to the exhaust conduit 96, and thetemperature sensor 184 is coupled to the engine 52. However, othersensor positions have been contemplated. For example, a temperaturesensor and/or pressure sensor may be coupled to the branch intakeconduit 74, the wastegate actuator 116, the wastegate 114, and/or theturbine bypass conduit 108. As previously discussed the controller 150may also send a control signal to the wastegate actuator 116 via signalline 117. The controller 150 may be included in a control system 190.The aforementioned sensors may also be included in the control system,in some examples. The intake conduits may be referred to as a firstintake conduit 74, a second intake conduit 64, depending on theirintroductory order in some examples. Likewise the exhaust conduits 96and 104 may be referred to as a first exhaust conduit, a second exhaustconduit, etc., depending on their introductory order.

FIG. 2 shows a second embodiment of the turbocharger system 54. FIG. 2includes some of the components in the turbocharger system 54 shown inFIG. 1, therefore similar parts are labeled accordingly. To avoidredundancy the similar components are not discussed with regard to FIG.2. However, it will be appreciated that the components may besubstantially identical.

The intake conduit 64 is shown in FIG. 2. However, the branch intakeconduit is omitted from FIG. 2. The air-cooled wastegate actuator 116 iscoupled to the intake conduit 64 in the embodiment shown in FIG. 2.Specifically, the air-cooled wastegate actuator 116 may be positionedwithin the intake conduit 64. In this way, air flowing through theintake conduit 64 may be flowed around the wastegate actuator to removeheat from the actuator. As a result, the likelihood of wastegateactuator thermal degradation is reduced, thereby increasing thelongevity of the wastegate actuator. No additional cooling systems maybe coupled to the air-cooled wastegate actuator, if desired. However, insome examples additional cooling systems may be used to cool thewastegate actuator.

FIG. 3 shows a detailed view of the branch intake conduit outlet 80,shown in FIG. 1. A portion of the intake conduit 64 is also depicted inFIG. 3. The intake conduit 64 includes a housing 320 defining a boundaryof an interior flow passage 322. As shown, an aspirator 300 (e.g.,venturi pump) may be included in the branch intake conduit outlet 80.The aspirator 300 includes an inlet 302, a throat 304, an outlet 306,and a vacuum port 308. The vacuum port 308 is in fluidic communicationwith upstream sections of the branch intake conduit 74. Arrows 310depict the general flow direction of air through the aspirator 300 andthe branch intake conduit 74. Arrows 312 depict the general flowdirection of air through the intake conduit. It will be appreciated thatthe aspirator 300 increases the airflow through the branch intakeconduit 74. As a result, a greater amount of intake air may be flowed tothe air-cooled wastegate actuator 116 shown in FIG. 1, increasing theamount of heat removed from the actuator. Consequently, the likelihoodof wastegate actuator thermal degradation is further reduced.

FIG. 4 shows a detailed view of the air-cooled wastegate actuator 116shown in FIG. 2. The intake conduit 64 includes a housing 400 defining aboundary of an interior flow passage 402. As shown, the air-cooledwastegate actuator 116 is positioned within an interior of the intakeconduit 64. Specifically, the air-cooled wastegate actuator 116 iscoupled to the interior of the housing 400 in the depicted example.Thus, the housing 400 at least partially surrounds the air-cooledwastegate actuator 116. Arrows 404 denote the general direction ofairflow through the intake conduit 64. However, it will be appreciatedthat the airflow pattern has greater complexity that is not depicted. Asshown, intake air is directed around the wastegate actuator 116, therebycooling the wastegate actuator 116. Therefore, the wastegate actuator116 receives airflow within the intake conduit 64. In this way, thelikelihood of thermal degradation of the wastegate actuator is reduced.

FIG. 5 shows another example air-cooled wastegate actuator 116. Thewastegate actuator 116 shown in FIG. 5 may be included in theturbocharger system embodiment shown in FIG. 1. The air cooler wastegateactuator 116 includes an air cooling passage 500. As shown, the aircooling passage 500 is in series fluidic communication with the branchintake conduit 74. In the depicted example, the air cooling passage 500extends into the air-cooled wastegate actuator 116. Thus, the aircooling passage 500 traverses the air-cooled wastegate actuator 116.Specifically, the air cooling passage spans a length of the air-cooledwastegate actuator 116. In some examples, the air cooling passage mayinclude a first section flowing air in a first direction and a secondsection flowing air in an opposite direction. However, other air coolingpassage configurations have been contemplated. For example, the aircooling passage may be coupled to a housing 502 of the air-cooledwastegate actuator 116 and traverse the housing.

FIG. 6 shows a method 600 for operation of a turbocharger system. Themethod 600 may be implemented via the systems (e.g., control system andturbocharger system) and components described above with regard to FIGS.1-5 or may be implemented via other suitable systems and components.

At 602 the method includes flowing intake air from an un-boosted intakeconduit (e.g., intake conduit 64, shown in FIG. 1) to a branch intakeconduit (e.g., branch intake conduit 74, shown in FIG. 1) in parallelfluidic communication with the un-boosted intake conduit. Next at 604the method includes flowing intake air from the branch intake conduitinto an air cooling passage (e.g., air cooling passage 500, shown inFIG. 5) included in an air-cooled wastegate actuator (e.g., air-cooledwastegate actuator 116, shown in FIG. 5).

At 606 the method includes flowing intake air back into the branchintake conduit from the air cooling passage. Next at 608 the methodincludes flowing intake air from the branch intake conduit back into theun-boosted intake conduit. In some examples, the intake air may beflowed from the branch intake conduit back into the un-boosted intakeconduit at a location downstream from where the intake air is flowedfrom the un-boosted intake conduit to the branch intake conduit. Furtherin some examples, the amount of air flowing through the branch intakeconduit may be adjusted via a valve positioned in the branch intakeconduit based on the temperature of the engine, for instance.

Note that in additional embodiments, a method for operating the enginemay include directing boosted intake air over a body of a wastegateactuator to cool the wastegate actuator. The boosted air may be directedto the wastegate actuator via a branch conduit leading from downstreamof the compressor to upstream of the compressor, for example in acompressor bypass line. The branch conduit may also be positioned fromupstream of the compressor to another position upstream of thecompressor. The wastegate actuator may be controlled by a control systemand receive electrical actuation signals from the control system. Thewastegate actuator may be mechanically coupled to the turbochargerwastegate to control operation of the wastegate during engine operation.

In some example, the amount of air directed to the wastegate actuator inthe branch intake conduit may be adjusted by a valve positioned in thebranch intake conduit. The valve may be adjusted by the controller basedon operating conditions. For example, exhaust temperature may beestimated by the controller and the valve in the branch intake conduitmay be increased as the exhaust temperature increases, thereby providingsufficient cooling to the wastegate actuator. Further, engine operationmay be adjusted based on the amount of airflow directed through thebranch intake conduit, and based on its temperature. For example,increased coolant may be provided to the charge air cooler in proportionto the amount and/or temperature of the airflow directed through thebranch intake conduit. As another example, compressor bypass valveoperation may be adjusted to compensate for the increased airflowthrough the branch intake conduit, in reverse proportion to one another.

Note that the example control and estimation routines included hereincan be used with various engine and/or vehicle system configurations.The specific routines described herein may represent one or more of anynumber of processing strategies such as event-driven, interrupt-driven,multi-tasking, multi-threading, and the like. As such, various acts,operations, or functions illustrated may be performed in the sequenceillustrated, in parallel, or in some cases omitted. Likewise, the orderof processing is not necessarily required to achieve the features andadvantages of the example embodiments described herein, but is providedfor ease of illustration and description. One or more of the illustratedacts or functions may be repeatedly performed depending on theparticular strategy being used. Further, the described acts maygraphically represent code to be programmed into the computer readablestorage medium in the engine control system.

It will be appreciated that the configurations and routines disclosedherein are exemplary in nature, and that these specific embodiments arenot to be considered in a limiting sense, because numerous variationsare possible. For example, the above technology can be applied to V-6,I-4, I-6, V-12, opposed 4, and other engine types. The subject matter ofthe present disclosure includes all novel and non-obvious combinationsand sub-combinations of the various systems and configurations, andother features, functions, and/or properties disclosed herein.

The following claims particularly point out certain combinations andsub-combinations regarded as novel and non-obvious. These claims mayrefer to “an” element or “a first” element or the equivalent thereof.Such claims should be understood to include incorporation of one or moresuch elements, neither requiring nor excluding two or more suchelements. Other combinations and sub-combinations of the disclosedfeatures, functions, elements, and/or properties may be claimed throughamendment of the present claims or through presentation of new claims inthis or a related application. Such claims, whether broader, narrower,equal, or different in scope to the original claims, also are regardedas included within the subject matter of the present disclosure.

The invention claimed is:
 1. A turbocharger system, comprising: aturbine positioned downstream of a combustion chamber; a turbine bypassconduit in fluidic communication with a turbine inlet and a turbineoutlet; a wastegate positioned in the turbine bypass conduit; anair-cooled wastegate actuator located in a branch intake conduit inparallel fluidic communication with an intake conduit positionedupstream of a compressor mechanically coupled to the turbine; and theair-cooled wastegate actuator adjusting a position of the wastegate, theair-cooled wastegate actuator receiving cooling airflow via the branchintake conduit from the intake conduit at an upstream location andflowing cooling air back into the intake conduit at a downstreamlocation.
 2. The turbocharger system of claim 1, where the air-cooledwastegate actuator is coupled to the branch intake conduit.
 3. Theturbocharger system of claim 1, where the air-cooled wastegate actuatoris positioned within an interior of the branch intake conduit andreceives intake airflow in the branch intake conduit.
 4. Theturbocharger system of claim 1, further comprising an aspiratorpositioned in an outlet of a first the branch intake conduit.
 5. Theturbocharger system of claim 1, where the intake conduit has a greatercross-sectional area than the branch intake conduit.
 6. The turbochargersystem of claim 1, where the air-cooled wastegate actuator includes anair cooling passage traversing a portion of the air-cooled wastegateactuator, the air cooling passage in series fluidic communication withthe branch intake conduit.
 7. The turbocharger system of claim 6, wherethe air cooling passage extends into the air-cooled wastegate actuator.8. The turbocharger system of claim 6, where the air cooling passagetraverses a housing of the air-cooled wastegate actuator.
 9. Theturbocharger system of claim 1, further comprising a charge air coolerpositioned downstream of the compressor.
 10. The turbocharger system ofclaim 1, where the wastegate adjusts exhaust gas flow through theturbine bypass conduit.
 11. The turbocharger system of claim 1, where noadditional cooling systems are coupled to the air-cooled wastegateactuator.
 12. A turbocharger system comprising: a turbine positioneddownstream of a combustion chamber; a turbine bypass conduit in fluidiccommunication upstream and downstream of the turbine; a wastegatepositioned in the turbine bypass conduit; and an air-cooled wastegateactuator adjusting a position of the wastegate, the air-cooled wastegateactuator coupled to a branch intake conduit upstream of a compressormechanically coupled to the turbine, the branch intake conduit inparallel fluidic communication with an intake conduit and having aninlet opening to the intake conduit at an upstream location and anoutlet opening to the intake conduit at a downstream location.
 13. Theturbocharger system of claim 12, where the air-cooled wastegate actuatoris mechanically coupled to the wastegate.
 14. The turbocharger system ofclaim 12, where the air-cooled wastegate actuator is a pneumaticwastegate actuator receiving boosted air from a second intake conduitpositioned downstream of the compressor.
 15. The turbocharger system ofclaim 12, where the air-cooled wastegate actuator is an electronicwastegate actuator receiving control signals from a controller.
 16. Amethod of cooling an actuator of a turbine wastegate valve comprising:flowing intake air from an un-boosted intake conduit to a branch intakeconduit in parallel fluidic communication with the un-boosted intakeconduit via adjusting a valve in the branch intake conduit; flowingintake air from the branch intake conduit into an air cooling passageincluded in an air-cooled wastegate actuator; and flowing intake airback into the branch intake conduit from the air cooling passage. 17.The method of claim 16, further comprising flowing intake air from thebranch intake conduit back into the un-boosted intake conduit.
 18. Themethod of claim 17, where the intake air is flowed from the branchintake conduit back into the un-boosted intake conduit at a locationdownstream from where the intake air is flowed from the un-boostedintake conduit to the branch intake conduit.